Pyrotechnic device



Patented Nov. 13, 1934 UNITED STATES reta l PYROTECHNIC DEVICE Herbert Clauser, Elkton, Md.

No Drawing. Application November 8, 1930,

Serial No. 494,452

8 Claims.

This invention relates to pyrotechnic devices and compositions, and more particularly to such devices and compositions intended to be ignited by abrasion or percussion and to burn slowly with intermittent or staccato detonations.

It is the general object of the present invention to provide a novel and improved pyrotechnic device and composition of the type described.

More particularly it is an object of the invention to provide in a pyrotechnic or firework of the type described an article devoid of the usual detrimental and toxic ingredients.

Another object of the invention comprises the provision of a pyrotechnic composition in which deterioration of the compound during and subsequent to manufacture is reduced or completely eliminated by the addition of normally inert ingredients.

A still further and important object of the invention consists in the introduction, in some stage of the manufacture of the composition, of a substance, the purpose of which is to lower the melting point of one of the active ingredients and by chemical combination therewith, or otherwise, to increase the activity of that ingredient whereby a non-toxic product may result which has all of the beneficial properties of the heretofore manufactured composition using toxic ingredients.

Other and further objects of the invention and features of the product will become more apparent to those skilled in the art of pyrotechnics as the description proceeds. It is to be understood that it is the intent of this application to cover by the appended claims all reasonable deviations from the subsequently disclosed formula both in proportion and in the substitution of well known equivalents.

The most prominent example of a firework of the type to which this invention relates is the toy or pyrotechnic known as spit devil, sonof-a-gun, devil chaser, or other trade names. These devices commonly consist of a molded disk of a suitable composition, often protected by a fancy paper wrapper, which is operated by placing the article on a hard surface, such as a sidewalk, and abrading the. same with the foot, for instance by a twisting movement or by striking or scratching the device on a rough abrasive surface.

This abrasive action, no matter how produced, or even the application of heat or flame causes the device to become ignited in one or more places whereupon certain parts of the composition burn slowly, exposing particles of the active ingredients which produce intermittent and staccato detonations or explosions which sometimes cause particles to be thrown off from the main part of the device to a considerable distance, often accompanied by a louder report. Said particles may then of their own accord continue to burnanddetonate and the whole body and particles jump about on the surface and in the air until the whole device is consumed.

' As heretofore manufactured such pyrotechnic devices contain as their active element white or yellow phosphorous and as an oxidizing agent a material such, for instance, as potassium chlorate. A third necessary ingredient is a suitable soluble gum, glue, or the like for initially forming a paste from which the articles can be molded. This agglutinant serves not only as a binder but as a fuel to promote the slow burning and serves also to isolate globules of the two active ingredients whereby small capsulesthereof are formed which produce the individual staccato reports. Othervingredients are often incorporated in the composition such for instance as red oxide of iron, red clay, or the like forthe purpose of retarding the burning and as a filler.

In manufacturing such devices, the phosphorous is preferably melted in a Warm solution of the gum arabic, or other glue, in water which thus forms, when dried, a protective coating about the phorphorous particles which is broken by the abrasion to expose the phosphorous to air where it ignites spontaneously,'takes oxygen from the oxidizing agent and produces the small explosions, and in so doing it both breaks away the enclose ing gum and ignites it causing the combustion to progress slowly through the composition until the whole article is consumed;

White, or yellow phosphorous as it is sometimes called, is a highly toxic poison and causes not only serious diseases to the workers but often causes fatalities on account of children putting the articles in their mouths, since they look like candy and are often mistaken for that by smaller children.

As long as these fireworks have been known efforts have been made to eliminate the toxic phosphorous and to manufacture an entirely nonpoisonous firework of this kind but until the present invention no one of these attempts has proven commercially successful.

The present inventioncontemplates,the substitution of an entirely non-poisonous composition for the toxic phosphorous without detrimental eifects on the functioning qualities of the firework. As examples of ingredients which may be substituted for the toxic white phosphorous may be mentioned the sesquisulfide of phosphorous, a material having the chemical formula P483 and sometimes known as tetraphosphortrisulfide and certain of the phosphorous derivatives of selenium such for instance as that one known as tetraphosphortriselenide and having the chemical formula P4893- These ingredients may be used separately along with the other necessary ingredients or may be combined in suitable proportions in the same composition.

As an example of a composition using the sulfur derivative of phosphorous the following may be noted in which the proportions given are those preferred but from which deviations may be made to vary the sensitivity, rate of explosion, and the like.

Parts by weight Gum arabic 180 Carbonate of magnesia" 55 sesquisulfide of phosphorous 65 Potassium chlorate 92 Inert filler 88 The composition is made by dissolving the gum in water and adding the dry ingredients other than the sesquisulfide of phosphorous in powdered form to make a suitable paste. The water is warmed to aid in the solution of the gum and to assist in the melting of the phosphorous compound.

It will be understood that the inert fillermay be any suitable substance such for instance as red clay having a high percentage of iron therein, red oxide of iron, or any other desirable inert substance since its function in the composition is entirely mechanical as previously explained. The carbonate of magnesia is an antacid and of course suitable equivalent materials may be substituted. The function of this material is to reduce or completely prevent the formation of hydrogen sulfide when the sesquisulfide of phosphorous comes into contact with the water. It also prevents and neutralizes any free acid during or subsequent to the manufacture and thus eliminates the possibility of spontaneous combustion such as may result by the contact of acid and p0- tassium chlorate.

In the attempted substitution of certain of the compounds and derivatives of phosphorous for free phosphorous, difficulty is often experienced in reducing these substitutes to a liquid form in order that they may be readily miscible with the other ingredients of the desired mixture. For instance, the red or amorphous variety of phosphorous has a melting temperature between 500 and 600 centigrade, whereas it ignites in atmosphere at approximately 260 centigrade, and thus cannot be melted except in the absence of active gases. Compounds of phosphorous and sulfur such as, for instance, tetraphosphortrisulfide, have a melting temperature of approximately 175 centigrade, while they ignite in air at around 100 centigrade. Where it is desired to mix phosphorous derivatives or substitutes with other ingredients in a liquid or plastic form, resort has been had to finely pulverizing the substitutes, which is often dangerous owing to their explosive and inflammable nature or else they must be reduced to a liquid state in the absence of air and other active gases, and the mixing must be done under such conditions.

In order to overcome the above difiiculties and to reduce the expense involved in the use of such phosphorous substitutes and derivatives, it has been found that the introduction of a trace of free phosphorous into the phosphorous derivative or compound either during or after its manufacture, results in materially lowering the melting temperature and in some cases, particularly in the case of the tetraphosphortrisulfide, the meltingtemperature is lowered to such a degree that the material is liquid at the temperature at which mixture of the ingredients is made. The amount of free phosphorous necessary to produce this result is very minute and not sufficient to affect the toxicity of the resultant mixture.

The addition of this trace of free, white phosphorous either directly into the mixture or by addition to the sesquisulfide of phosphorous prior to its incorporation into the mixture is believed to have additional beneficial results. The phosphorous in the phosphorous sesquisulfide exists as an unsaturated molecule and the addition of the free phosphorous results in a chemical reaction wherein at least a portion of the free phosphorous combines with the composition to produce one or more of the phosphorous sulfur compounds of which the chemical formula: are at present known but the exact ones of the compounds formed are unknown.

It is known that phosphorous and sulfur will combine into at least five chemically different compositions, some of which are at least as active as free phosphorous whereas the sesquisulfide of phosphorous is not so active. It has been found upon careful experiment that the additional phosphorous, either that remaining in its free state or that forming the additional compounds increases the activity of the sesquisulfide of phosphorous at least to the extent of forming an'initiating ingredient therefor which materially augments the operation of the device and produces a highly satisfactory commercial article. It is therefore preferred to use as the material which lowers the melting point of the sesquisulfide of phosphorous such a quantity of free phosphorous (hardly more than a trace) that the remaining free phosphorous in the completed composition is insufficient to have toxic effects.

As an example of a composition using a selenium derivative of phosphorous the following may be given with the understanding that it is subject to the same variations and substitutions as is the original formula.

Parts by weight Gum arabic 160 Carbonate of magnesia Selenium derivative of phosphorous Potassium chlorate 86 Inert filler '70 This composition is improved as is the first mentioned composition, by the addition of a material or materials which lower the melting point of the selenium derivative and provide the initiating feature and for this purpose either additional selenium derivatives of phosphorous may be used or a small quantity of free phosphorous, the ensuing reaction producing small quantities of some of the known compounds which are remarkably active and sufficiently non-toxic for all purposes.

Both the tetraphosphortrisulfide and the selenium derivatives of phosphorous, although containing combined phosphorous possess none of the toxic properties thereof nor any others of their own, It is well known that the toxicity of phosphorous is confined to the allotropic, modified form known as white or yellow phosphorous while other forms and compounds of phosphorous of different chemical properties have no toxic effect upon the human body. In the claims the expression compound of phosphorous and one of the sulphur selenium group or a similar expression, refers to such a composition of phosphorous and sulphur or phosphorous and selenium as will function in the firework of the type described in this application.

Another very great advantage of the present invention results from the fact that the phosphorous derivatives employed may be handled with impunity during the manufacture of the firework.

Either of the formulae cited above may be modified by the substitution therein, for a portion of the phosphorous derivative, of a quantity of the phosphorous derivative used in the other formula. With this combination it will be found that initiating means or melting point lowering ingredients are seldom necessary.

It will be understood that the invention is not limited to the aforementioned derivatives of phosphorous as many non-toxic derivatives of phosphorous or variations of the derivatives mentioned above may be produced by those skilled in the art. A great many of these derivatives are not pure but are combinations of various phosphorous compounds. In fact the invention in its broadest aspects includes the substitution for the toxic phosphorous in the usual pyrotechnic composition o-f any non-toxic compound having sufficient activity to ignite on exposure to air and cause explosion by combining with an oxidizing agent incorporated in the composition.

This invention is a continuation in part of my application, Serial No. 92,942 for Pyrotechnic devices, filed March 6, 1926.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A firework adapted to be ignited by abrasion.

and to burn slowly with intermittent detonations including in combination, an oxidizing agent, a compound of phosphorous and an element of the sulphur selenium group and having a melting point above its ignition point, and sufficient free phosphorous to reduce the said melting point below the ignition point.

2. A firework adapted to be ignited by abrasion and to burn slowly with intermittent detonations including in combination, an oxidizing agent, a non-toxic phosphorous compound with an element of the sulphur selenium group, an agglutinant, and suiiicient free phosphorous to lower the melting point of the compound below its ignition point.

3. A firework adapted to be ignited by abrasion and to burn slowly with intermittent detonations including in combination, an oxidizing agent, a non-toxic phosphorous compound with an element of the sulphur selenium group, an agglutinant, an antacid, a filler and sufiicient phosphorous derivative of substantially the activity of free yellow phosphorous to lower the melting point of the compound below its ignition point.

4. A composition for fireworks adapted to be ignited by abrasion and to burn slowly with intermittent detonations including in combination, in approximately the following proportions, a water soluble agglutinant 180 parts; an antacid 55 parts; sesquisulphide of phosphorous 65 parts; an oxidizing agent 92 parts; an inert filler 88 parts and suificient free yellow phosphorous to reduce the melting point of the sesquisulphide of phosphorous to substantially atmospheric temperature.

5. A composition for fireworks adapted to be ignited by abrasion and to burn slowly with intermittent detonations, including in combination, an oxidizing agent, a selenide of phosphorous, an agglutinant and free phosphorous in sufiicient quantity to lower the melting point of the selenide below its ignition point.

6. A composition for fireworks adapted to be ignited by abrasion and to burn slowly with intermittent detonations including in combination in approximately the following proportions, a water soluble agglutinant 160 parts; an antacid 42 parts; a selenium derivative of phosphorous 60 parts; an oxidizing agent 86 parts and an inert filler 70 parts.

7. A firework composition comprising an agglutinant; an oxidizing agent; a non-toxic selenium derivative of toxic phosphorous; a filler and a phosphorous selenium derivative of substantially the activity of free phosphorous.

8."A composition for fireworks adapted to be ignited by abrasion and to burn slowly with intermittent detonations including in combination in approximately the following proportions, a water soluble agglutinant 160 parts; an antacid 42 parts; a selenium derivative of phosphorous 60 parts; an oxidizing agent 86 parts, an inert filler 70 parts and sufiicient free prosphorous to lower the melting point of the selenium derivative of phosphorous below its ignition point.

HERBERT CLAUSER. 

